1. Technical Field
The present invention relates to an anthracene derivative and an organic electroluminescent device using the same. More specifically, the present invention relates to an anthracene derivative which enables production of an organic electroluminescent device having excellent power and luminance efficiencies and a long service life, and an organic electroluminescent device using the same.
2. Background Art
An organic electroluminescent device (hereinafter, referred to as “organic EL device”) is an active light-emitting display device taking advantage of the phenomenon that light of a particular wavelength is emitted with the exciton transition from an exited state to a ground state in energy level, after formation of excitons from recombination of electrons and holes following the injection of electrons and holes into a fluorescent or phosphorescent organic compound thin film (hereinafter, referred to as “organic film”) formed between a first electrode for hole injection (anode) and a second electrode for electron injection (cathode). The organic EL device has various advantages such as the feasibility of weight reduction, simple structure using small numbers of components and parts, simplified manufacturing process, fast response speed, wide viewing angle with high definition, and the like. Further, the organic EL device enables perfect realization of a high-fidelity moving image, the feasibility of high-color purity in conjunction with ultra-slimness, compactness and lightweight in consideration of weight and size, and low power consumption and low driving voltage. That is, organic EL devices have electrical properties suitable for use in portable electronic devices and instruments.
Representative examples of earlier organic EL devices include those having a monolayer structure disclosed in patents issued to Gurnee (U.S. Pat. Nos. 3,172,862 and 3,173,050) in 1969. However, these devices suffer from difficulty in practical application thereof, due to a need for an excessive driving voltage of 100 V or higher. In order to solve such a problem, a multilayer organic EL device having a significantly low driving voltage of about 6 to 14 V was proposed by Tang et al (Eastman Kodak Co.) in 1987 (C. W. Tang et al., Appl. Phys. Let., 51, 913 (1987); J. Applied Phys., 65, 3610 (1989); and U.S. Pat. No. 4,356,429). Currently, there is a continuing trend toward the development of organic EL devices having a variety of functional stack structures including a hole-injection layer, a hole-transport layer, an electron-transport layer and an electron-injection layer.
Meanwhile, conventional organic EL devices employ anthracene and its derivative for a variety of desired applications. For example, there have been proposed techniques of using 9,10-di(2-naphthyl)anthracene, also known as “ADN” (U.S. Pat. No. 5,935,721), 9-naphthyl-10-phenylanthracene derivatives (U.S. Pat. Application Publication No. 2006/0014046 A1) and 9-biphenyl-10-naphthylanthracene derivatives (WO 2005/080527) as a host material of a light-emitting layer, and a technique of improving a service life of an organic EL device via use of bis-anthracene as a light-emitting layer material (U.S. Pat. No. 6,534,199). Further, a technique of using an anthracene derivative in a hole-transport layer (HTL) has been also suggested (U.S. Pat. Nos. 6,465,115 and 5,759,444). Further, there are also known various uses and applications of anthracene and anthracene derivatives in organic EL devices.
As discussed above, even though a great deal of research and study has been made on introduction of anthracene in the organic EL device, prior art technologies do not sufficiently satisfy desired properties such as luminance, efficiency, driving stability and lifespan. Therefore, there is an urgent need for development of various techniques capable of solving such problems. Particularly, in a host-guest system which is based on an energy transfer principle for doping a host of a light-emitting layer with a dopant, there is a need for intense study and research on novel anthracene derivatives as a host material of the light-emitting layer.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.